# Homework Assignment #3 Due 2 August 2011 4.44 Phosphorus

```Homework Assignment #3
Due 2 August 2011
4.44 Phosphorus forms many oxoacids. Indicate the oxidation number of
phosphorus in each of the following acids: (a) HPO3, (b) H3PO2, (c) H3PO3, (d)
H3PO4, (e) H4P2O7, (f) HSP3O10
4.64 Calculate the molarity of each of the following solutions: (a) 6.57 g of
methanol (CH30H) in 1.50 x lO2 mL of solution, (b) 10.4 g of calcium chloride
(CaClz) in 2.20 x lO2 mL of solution.
4.86 Calculate the concentration (in molarity) of an NaOH solution if 25.0 mL of
the solution is needed to neutralize 17.4 mL of a 0.312 M HCl solution.
6.16 The blue color of the sky results from the scattering of sunlight by molecules
in the air. The blue light has a frequency of about 7.5 x 1014 Hz. (a) Calculate the
wavelength (in nm) associated with this radiation, and (b) calculate the energy (in
joules) of a single photon associated with this frequency.
6.64 Give the values of the four quantum numbers of an electron in the following
orbitals: (a) 3s; (b) 4p; (c) 3d.
6.92 Write the ground state electronic configuration for the following elements:
B, V, C, As, I, Au.
7.18 Group the following electron configurations in pairs that would represent
elements with similar chemical properties:
(a) 1s22s22p63s2
(b) 1s22s22p3
(c) 1s22s22p63s23p64s23d104p6
(d) 1s22s2
(e) 1s22s22p6
(f) 1s22s22p63s23p3
7.32 On the basis of their position in the periodic table, select the atom with the
largest atomic radius in each of the following pairs: (a) Na, Si; (b) Ba, Be; (c) N, F;
(d) Br, Cl; (e) Ne, Kr
7.58 Write the ground state electronic configuration of the following ions:
(d) F-; (e) S-2; (f) Al+3; (g) Se-2; (h) Br8.4 Write the Lewis dot symbols for the following ions: (a) Li+; (b) Cl-; (c) S-2; (d)
Sr+2; (e) N-3
```